Lets take a peek at your network environment:
First:
Power Cycle everything . . Turn off the Modem, router and all pc's . . turn on the Modem and wait a few minutes for the lights to stabilize . . then turn on the router, then one pc at a time. See if you connect to the internet.
Then:
Remove all the stored wireless network profiles and search for the network again.
How to Remove Stored Wireless Network Profiles for XP, Vista, and Windows 7
Then: check your browser's settings, remove any proxy settings if found
here's how.
Then:
with the pc connected to the router, Click on
Start . .
Run . . type
CMD
At the > prompt type type the following command:
IPCONFIG /ALL
Note that there is a space before the /ALL, but there is NOT a space after the / in the following command.
Right click in the command window and choose
Select All, then hit
Enter. Come back here and Paste the results in a message.
If you are on a machine with no network connection, use a floppy, USB disk, or a CD-RW disk to transfer a text file with the information to allow pasting it here.
then please Download and run this
Xirrus Wi-Fi Inspector, click the
Networks link on the upper left and paste a screen shot of that screen here. Note that this application requires
NET Framework to run. If you get an error about a missing function, download and install NET Framework.
To post a screen shot of the active window, hold the
Alt key and press the
PrtScn key. Open the Windows PAINT application and
Paste the screen shot. You can then use PAINT to trim to suit, and save it as a JPG format file. To upload it to the forum, open the full reply window and use the
Manage Attachments button to upload it here.